| /* |
| * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.swing.undo; |
| |
| import java.io.Serializable; |
| import javax.swing.UIManager; |
| |
| /** |
| * An abstract implementation of <code>UndoableEdit</code>, |
| * implementing simple responses to all boolean methods in |
| * that interface. |
| * |
| * @author Ray Ryan |
| */ |
| @SuppressWarnings("serial") // Same-version serialization only |
| public class AbstractUndoableEdit implements UndoableEdit, Serializable { |
| |
| /** |
| * String returned by <code>getUndoPresentationName</code>; |
| * as of Java 2 platform v1.3.1 this field is no longer used. This value |
| * is now localized and comes from the defaults table with key |
| * <code>AbstractUndoableEdit.undoText</code>. |
| * |
| * @see javax.swing.UIDefaults |
| */ |
| protected static final String UndoName = "Undo"; |
| |
| /** |
| * String returned by <code>getRedoPresentationName</code>; |
| * as of Java 2 platform v1.3.1 this field is no longer used. This value |
| * is now localized and comes from the defaults table with key |
| * <code>AbstractUndoableEdit.redoText</code>. |
| * |
| * @see javax.swing.UIDefaults |
| */ |
| protected static final String RedoName = "Redo"; |
| |
| /** |
| * Defaults to true; becomes false if this edit is undone, true |
| * again if it is redone. |
| */ |
| boolean hasBeenDone; |
| |
| /** |
| * True if this edit has not received <code>die</code>; defaults |
| * to <code>true</code>. |
| */ |
| boolean alive; |
| |
| /** |
| * Creates an <code>AbstractUndoableEdit</code> which defaults |
| * <code>hasBeenDone</code> and <code>alive</code> to <code>true</code>. |
| */ |
| public AbstractUndoableEdit() { |
| super(); |
| |
| hasBeenDone = true; |
| alive = true; |
| } |
| |
| /** |
| * Sets <code>alive</code> to false. Note that this |
| * is a one way operation; dead edits cannot be resurrected. |
| * Sending <code>undo</code> or <code>redo</code> to |
| * a dead edit results in an exception being thrown. |
| * |
| * <p>Typically an edit is killed when it is consolidated by |
| * another edit's <code>addEdit</code> or <code>replaceEdit</code> |
| * method, or when it is dequeued from an <code>UndoManager</code>. |
| */ |
| public void die() { |
| alive = false; |
| } |
| |
| /** |
| * Throws <code>CannotUndoException</code> if <code>canUndo</code> |
| * returns <code>false</code>. Sets <code>hasBeenDone</code> |
| * to <code>false</code>. Subclasses should override to undo the |
| * operation represented by this edit. Override should begin with |
| * a call to super. |
| * |
| * @exception CannotUndoException if <code>canUndo</code> |
| * returns <code>false</code> |
| * @see #canUndo |
| */ |
| public void undo() throws CannotUndoException { |
| if (!canUndo()) { |
| throw new CannotUndoException(); |
| } |
| hasBeenDone = false; |
| } |
| |
| /** |
| * Returns true if this edit is <code>alive</code> |
| * and <code>hasBeenDone</code> is <code>true</code>. |
| * |
| * @return true if this edit is <code>alive</code> |
| * and <code>hasBeenDone</code> is <code>true</code> |
| * |
| * @see #die |
| * @see #undo |
| * @see #redo |
| */ |
| public boolean canUndo() { |
| return alive && hasBeenDone; |
| } |
| |
| /** |
| * Throws <code>CannotRedoException</code> if <code>canRedo</code> |
| * returns false. Sets <code>hasBeenDone</code> to <code>true</code>. |
| * Subclasses should override to redo the operation represented by |
| * this edit. Override should begin with a call to super. |
| * |
| * @exception CannotRedoException if <code>canRedo</code> |
| * returns <code>false</code> |
| * @see #canRedo |
| */ |
| public void redo() throws CannotRedoException { |
| if (!canRedo()) { |
| throw new CannotRedoException(); |
| } |
| hasBeenDone = true; |
| } |
| |
| /** |
| * Returns <code>true</code> if this edit is <code>alive</code> |
| * and <code>hasBeenDone</code> is <code>false</code>. |
| * |
| * @return <code>true</code> if this edit is <code>alive</code> |
| * and <code>hasBeenDone</code> is <code>false</code> |
| * @see #die |
| * @see #undo |
| * @see #redo |
| */ |
| public boolean canRedo() { |
| return alive && !hasBeenDone; |
| } |
| |
| /** |
| * This default implementation returns false. |
| * |
| * @param anEdit the edit to be added |
| * @return false |
| * |
| * @see UndoableEdit#addEdit |
| */ |
| public boolean addEdit(UndoableEdit anEdit) { |
| return false; |
| } |
| |
| /** |
| * This default implementation returns false. |
| * |
| * @param anEdit the edit to replace |
| * @return false |
| * |
| * @see UndoableEdit#replaceEdit |
| */ |
| public boolean replaceEdit(UndoableEdit anEdit) { |
| return false; |
| } |
| |
| /** |
| * This default implementation returns true. |
| * |
| * @return true |
| * @see UndoableEdit#isSignificant |
| */ |
| public boolean isSignificant() { |
| return true; |
| } |
| |
| /** |
| * This default implementation returns "". Used by |
| * <code>getUndoPresentationName</code> and |
| * <code>getRedoPresentationName</code> to |
| * construct the strings they return. Subclasses should override to |
| * return an appropriate description of the operation this edit |
| * represents. |
| * |
| * @return the empty string "" |
| * |
| * @see #getUndoPresentationName |
| * @see #getRedoPresentationName |
| */ |
| public String getPresentationName() { |
| return ""; |
| } |
| |
| /** |
| * Retreives the value from the defaults table with key |
| * <code>AbstractUndoableEdit.undoText</code> and returns |
| * that value followed by a space, followed by |
| * <code>getPresentationName</code>. |
| * If <code>getPresentationName</code> returns "", |
| * then the defaults value is returned alone. |
| * |
| * @return the value from the defaults table with key |
| * <code>AbstractUndoableEdit.undoText</code>, followed |
| * by a space, followed by <code>getPresentationName</code> |
| * unless <code>getPresentationName</code> is "" in which |
| * case, the defaults value is returned alone. |
| * @see #getPresentationName |
| */ |
| public String getUndoPresentationName() { |
| String name = getPresentationName(); |
| if (!"".equals(name)) { |
| name = UIManager.getString("AbstractUndoableEdit.undoText") + |
| " " + name; |
| } else { |
| name = UIManager.getString("AbstractUndoableEdit.undoText"); |
| } |
| |
| return name; |
| } |
| |
| /** |
| * Retreives the value from the defaults table with key |
| * <code>AbstractUndoableEdit.redoText</code> and returns |
| * that value followed by a space, followed by |
| * <code>getPresentationName</code>. |
| * If <code>getPresentationName</code> returns "", |
| * then the defaults value is returned alone. |
| * |
| * @return the value from the defaults table with key |
| * <code>AbstractUndoableEdit.redoText</code>, followed |
| * by a space, followed by <code>getPresentationName</code> |
| * unless <code>getPresentationName</code> is "" in which |
| * case, the defaults value is returned alone. |
| * @see #getPresentationName |
| */ |
| public String getRedoPresentationName() { |
| String name = getPresentationName(); |
| if (!"".equals(name)) { |
| name = UIManager.getString("AbstractUndoableEdit.redoText") + |
| " " + name; |
| } else { |
| name = UIManager.getString("AbstractUndoableEdit.redoText"); |
| } |
| |
| return name; |
| } |
| |
| /** |
| * Returns a string that displays and identifies this |
| * object's properties. |
| * |
| * @return a String representation of this object |
| */ |
| public String toString() |
| { |
| return super.toString() |
| + " hasBeenDone: " + hasBeenDone |
| + " alive: " + alive; |
| } |
| } |